Paleomagnetism is the study of natural remnant magnetization of the Earth's materials in order to determine the itensity and direction of the Earth's magnetic field in the geologic past. Variations in the Earth's magnetic field can be used as a means of stratigraphic correlation. Major reversals of the Earth's magnetic field are well known and the record of these reversals in sediments can be used as time markers or chronostratigraphic horizons.
